用于静态/动态复合信号的改进对称解调技术  

Corrected Symmetrical Demodulation Method for Static/Dynamic Composite Signals

作　　者：贾景善 Jia Jingshan(College of Communication and Information Technology,Xi'an University of Science and Technology,Xi'an 710054,Shaanxi,China)

机构地区：[1]西安科技大学通信与信息工程学院,陕西西安710054

出　　处：《光学学报》2023年第23期39-44,共6页Acta Optica Sinica

基　　金：国家自然科学基金青年科学基金(62305265);陕西省自然科学基础研究计划(2022JQ-613)。

摘　　要：提出一种可测量外腔式Fabry-Perot传感器所加载的静态/动态复合信号的腔长自补偿改进对称解调技术。在对称解调技术的基础上,通过其输出信号的直流量判断传感器腔长的变化,从而划分腔长稳定段与突变段,分段并重新进行信号解调,以保证动态分量的解调精度;同时利用腔长变化前后计算出的干涉信号相位差对腔长的变化量进行补偿,以提高静态分量的测量精度。实验证明该解调技术能够实现对静态/动态复合信号的测量。实验中实现了幅度超过100μm复合信号的解调,大幅度腔长变化量的测量误差约为2%。该解调技术能够解调不同腔长传感器上加载的包含高频分量的静态/动态复合信号。Objective Extrinsic Fabry-Perot interferometers(EFPIs)are widely used in fiber optic sensors.In many applications,the measurand is a mixture of static and dynamic signals.However,laser interference demodulation algorithms used for dynamic signal measurement are significantly different from white light interference demodulation algorithms used for static signal measurement.Laser interference demodulation algorithms require laser wavelengths to remain stable,while white light interference demodulation algorithms require wavelength scanning to obtain the spectrum of the sensor to achieve measurement.Therefore,these measurement techniques can only measure different dynamic signals or different static signals and cannot achieve measurement of static/dynamic composite signals.For EFPI sensors,it is expected to achieve the measurement of static/dynamic composite signals through high-speed white light interferometry demodulation technologies.However,these demodulation technologies are still unable to meet the measurement requirements of high-frequency signals due to limitations in scanning speed.Some high-speed white light interferometry demodulation technologies rely on high-tuning-speed laser sources,but the bandwidth of such light sources is narrow,which limits the measurement range.At the same time,this type of technology requires a large amount of calculations and sometimes requires offline signal processing.Various laser interference demodulation algorithms have been proposed to extract dynamic signals from EFPI sensors.However,these demodulation techniques will collapse if the EFPI cavity length changes significantly since the cavity length and laser wavelengths must be strictly matched to obtain orthogonal signals.In this article,a correction symmetrical demodulation method for the measurement of static/dynamic composite signals is proposed.Static/dynamic composite signal demodulation is experimentally demonstrated.Methods The change in sensor cavity length is judged by the direct current component of the output

关 键 词：光纤光学 光纤传感技术 激光干涉测量 相位解调 外腔式Fabry-Perot干涉仪 

分 类 号：TN253[电子电信—物理电子学]